Stop-motion device for knitting machines with latch needles



Oct. 17, 1961 H. LUMK 3,004,417

STOP-MOTION DEVICE FOR KNITTING MACHINES WITH LATCH NEEDLES Filed March 19, 1958 IN V EN TOR.

@2161? larym k United States Patent O 3,004,4'17 STOP-MOTION DEVICE FOR KNITTING MACHINES WITH LATCH NEEDLES Hynek. Lufiak, Trebic Czechoslovakia, assignor to Zapadomorav s'ke strojirny, narodni podnik, Trebic,

Czechoslovakia r .Filed Mar. 19, 1958, Ser. No; 722,405 Claims priority, application Czechoslovakia Mar. 25, 1957 15 Claims. (Cl. 66--157) The invention relates to circular knitting machines operating with latch needles, and more particularly to a stop-motion device which is actuated by released needle latches and comprises a pivotally mounted feeler and two electric contacts which are arranged to coact in a substantially closed casing.

In knitting machines of the kind mentioned very delicate needles are used and have latches pivotally mounted in the body of the needles. It is well known, that the latches of these needles are maintained in the closed position by the yarn proper during the knitting operation. When for any reason the yarn breaks, the released latch of the needle pivots outwardly. This happens particularly in circular knitting machines wherein the needles are caused to move along a circular path and the latches are subjected to the action of centrifugal force so that the latches in the, absence of yarn assume a radial position.

' The prompt detection of such a released latch of a needle isof importance and should be followed by automatic and immediate stopping of the machine as in the case of a broken or not properly tensioned yarn. An open latch 3,004,417 Patented Oct. 17., 1961 ICC lateral deflectionof the feeler member causes at the .same time a turning of the movable electric contact for engagement with the fixed electric contact. The movable contact must, however, be in such'a position that no contact takes place between the contacts when the feeler member is in its position of readiness for operation; on

the other hand, the distance between the contacts must be so small that the deflection required for the engagement of the contacts should not be too great, considering the circular path of a released needle. latch.

The above mentioned drawbacks are overcome by the device according to the invention, according to a basic feature of which the movable electric contact is mounted within a casing on a pin adjacent to the fixed electric contact which is supported by the lid of the casing.. A gap is formed between the head of the fixed con- .tact and the movable contact, which gap is maintained by I jecting out of the casing. The abutment of the arm of the is commonly detected by a pivotal feeler member of the r stop-moticn device, which member, when it is engaged by a released latch ofa needle, actuates electric contacts to close an electric circuit for stopping of the machine. In view of the factlthat the latch, particularly of thin needles is a very delicate element, it'is important that the feeler member react immediately upon its contact with a released latch without subjecting the latch to any ap preciable force. Otherwise, the latch would be bent or broken when it engages the feeler member. 'It is therefore important that the feeler member and the switching members are so arranged that the force required for their operation, i.e. for the pivotal movement of the feeler member and for the closing of the electric circuit, should be very small and should not be able to damage the released latch.. The necessary pivotal movement of the feeler member should also be as small as possible in view of the fact that the pointed end or the open latch quickly loses contact with the pointed end of the feeler member because of its movement along a circular path. Moreover, it must be possible to adjust the feeler member into the operational position, i.e,. into a position very near to the latches of the needles, in a simple and accurate manner.

In a recently proposed stop-motion device actuated by released'needle latches, wherein a pivotall'y'mounted feeler member and two electric contacts are used'and the feeler member is deflected when it is en-gagedby an open latch of a needle, the feeler member together with the movable electric contact forms a single unit, and one arm of the'rnovable contact is arranged to lift the free end of the" hired contact, which is resiliently mounted, so that the arm of the movable contactis free toengage an opening in the fixed contact and to complete the current circuit.

The rigid connection of the movabl'e'contact with. the

feeler memberso thatthey form a unit has, however, the disadvantage that the relative position of the movable and fixed electric contacts varies with the'result that a tedious adjustment of the feeler member is required. The

trigger pawl against the inner wall of the casing, and

the movement of the tooth of the trigger pawlinto' the recess of the movable contact are actuated by a tension spring which is linkedto the movable contact and .to the trigger pawl and thus actuates' themovements ofboth these members.

The invention will now be described in more detail withreference to an embodiment thereof shown in the accompanying drawings, wherein A FIG. 1 represents a perspective view of the stop-motion device actuated by released needle latches, the feeler member being shown in a position of readiness to operate,

FIG. 2 shows a vertical section along the plane a-a of the device of FIG. 1,

3 is a plan view of the device of FIG. 1 without lid, showing the feeler member in its position of readiness,

FIG. 4 is a plan view of the device of FIG. 1 with-the lid of the casing removed, showing the feeler member in its operating position, and r I FIG. 5 is a fragmentary section along the plane b--b of FIG. 4. r

The stop-motion device sensitive to the position of the latches of the needles consists of a. feeler member 1 with a widened flat end 2 which is adapted to be engaged by released or open latches 3 of needles 4 which move on acircular path determined by the needle cylinder of,

a circular knitting machine. The feeler member 1 is adjustably mounted by means of. a screw 6 in a. connecting member 5, and his freeto carry out a pivotal movement to assume either the poistion of readiness I (FIG. 3) or the operating position II (FIG. 4)., The connecting member 5 is fastened by means of a screw 8 to a vertical spindle 7 which is rotatably mounted within a sleeve 9 which forms an integral unit with a casing 10 fixed-to the upper end of the sleeve.- The sleeve.9 is adjustably mountedin a holder-or support 11 so that it can be rotated about its axis and shifted in a vertical position and then adjusted in this position by means of a screw 12, whereby the whole stop-motion device can be adjusted into the required position with respect' to the needles 4. The upper end of the spindle 7 projects .into the casing 10 and carries, firmly connected to it, a

trigger pawl .13. [which "has .a .formiofsa bell-cr-ank lever one arm 14 of which has at its end a tooth 15 and normally rests against the inner face of the wall 16 of the casingi10avhereby thezpositidnzof creadinessl zofithe feelenr men1be-r .-isidcterminedi i The others ;a=rmi.t17 f the pawl 13 is attached to---one;.lendr-' of al-ttension springe -18; the a ing islclosedby :meansof-a lid 24 rconsisting -of.;a transparent material; The-didaistastened EtO thC. casing by; meansof a screwizszand forms an=-insulating carrienfor-s the-= fixedcontact .which i-is' formed -by :a screw .26; andvis fastened to: the lid '24by: means;:of;-a nut. 27 i'intsuchs a -m'a-nnerathat :the head-28 20f therscrew; canxbe contacteda -by thermovablezcontact 19 :(FIGS; 4.and. ').=vv In; this' way; the: lid 24;permits;inspection of the; mech-= anisms-within the :casing without removal ofxthe. lidv 24: An electric:lead 129:1's fastened betweem-the1.-lidv 24 and the'nut 27: v

The-"described device operates as follows: During the knitting: of theleg ofhose,.for' instance,v

when-defects hardly occur, the feelenmember -is in its:

position of readiness 1 (FIG: 3), i.e.- radially: adjacent the needles 4 which move along. a rcircle'ias indicated by the: :arrow. The mova-ble' electric; contact :19 is spaced: from the head-28 of thefixed electric contact 26 so that the electric circuit*:isinterrupted. A predetermined gap x: (FIG; 2)pseparates-thei movable contact 19 fromfther head 28 of the fixed contact 26 whenthetrigger pawl 13: with -its-arm' 14 abuts against the-inner face ofrtherwallr 16 of the casing 10, ie when the feeler member 1 isinits-positionxofi-readiness =1." The::tooth tiat; the same time holds-the movable contact 19 in position: against :the:

force of the tension spring-18. ln- -the case of a defect whenthe latch3 of anyone of the needlesi4 is' in theopen orreleased position- {FIG 4), the feelers member .1 lisf-engagedby a latch: tat-sits; end 2, and is pivoted in the direction of the arrow,-:i.e

from'-the position of readiness I into the :operating .posi

t-ion II. As a result of the pivotal movement .oflthe feeler:

member; the/spindlefl is' caused to rturn with the trigger pawl :13' attached-sto it: Theturningxmovemen't 1s 1113a clockwise direction, as seen in FIGS. 3 and 4. The tooth;

115 Ofith6 arm r142 isl -aligned ion-engagement: with the recess' ofthe movablev contact-19 so thattheymovable contact is free to turn aboutwits yertical p1n21 and; is

pulled by-"the spring-e -18;against 1 the head 28: of the fixed contact 26 (FIG. 5). an electric: circuit, 3 electro-magnet'ic. circuitmembers,

known per S6,---8;=I'e:2 actuatedi'zand; cause. an; immediate: stoppingof theemachinei After the defect; hasbeen :removed,- the :machinecis switched. on again'by manually moving-- the freeinsulatediendczz .of' the movable-electric contact-19in adirection away from .thefixedcontact: 26* until the t1'-igger-paw1-.L13,' the. spindlefl :and the hfeelen member 1 can be returned by. the tension spring, 18. ,-;mto

the positio'n of readiness -I I(FIG. 3)'.1

The device according to the invention .is intended mainly; for use in connectiomwith circular knitting machines with:

latch needles- 'for the manufacture of seamless hosiery,

but his not-limited to-the manufacture-of this typenofi articles and maybe likewise used in circularknitting-ma chines" with latch needles for the manufacture: of other- 7 1., In }a stop rnotion arrangementfor a knitting ma n ted ab ic -r What ,I claim is; V

chineg in combination, a support; a first contact member fixedly; mounted on saidsupport; asecond contact ment ber mounted'on saidsupport, said second member' be'ing Closing of the contacts completes permanently connectedto said feeler member for joint movement therewith about-said axisg" abutment means on" said trigger member for abutmentagainsttsaidmovable second contact member when-:saidieele'n member is in said firsbpositionthereofso. asto selectively prevent move-1 ment of said secondscontacti member;v into engagement with said first contact member; resilient means for urging SZIidiiSECOHdjICOIltflCI member to move into; engagement with: saidfirst; contactzmember; and for urging said- I feeler 1 member to move fromasaid'second;towards;said first-posi-v tion 1 thereof and za;;pluralityof latch tneedies each having :a latch". movableq-toward andwawaytfrom,-an.-;open

position, each needle being mounted zformovement in an arcuate pathejrelative";to;-saidi;support and-forabutmentxof' ,rsaidtlatch :thereofagainst, said; feeler; member 7 when said.da.tch :is ;-in: the open (position: thereof during saidtzmovementqofisaid-;needle, and saidfeeler member is 1' in said :first position thereof;

2.: In arrangement as set forth nin -qclaim Q 1, said feeler :1 member; and; said triggermember: being fixedly connected. 1;

3. In:anzarrangement astset torthPin-claim. 1,. said resilient means being :;a :eresilient rmember I having spaced portions respectively secured tosaid second contact memberiand said tfeeler; member for :l g S d :second tactzmember; and lsaidigfeeler member for urging said second: cont-act member v to, move into i engagement with said first-contact member gand for simultaneously urging said feeler member-11o {movetowards saidafirst. position 3 thereof..: g, a

4. 7. In an; arrangementas set forthpin, claim. :3, said: second.contact-membenrbeing movableiin a predetermined. -directionl;; for:closing; said stopaetioncircuit,- and said feeleramembergphaving an actuating element: fixedly, sew, cured t-henetm;v saidactuatine e men moving, in -3 tion opposite.- :to; said predetermined direction zwhen, said feelers member;- ;mo.ves towards ,said firSt, position thereof, saidresilient member permanently urging saiducontact. member-,5 and c said actuati g element to move, in said. predetermined and in said-opposite direction respectively.

5., In an arrangement: as set-,forth .in claimfll, said. latch .-ne e dle,- being rnovably mounted for. movement .of v the-latch of; said needle: in a predetermined direction and path whe aseid latchrisin the open position thereof, said feeler memberiprojectingt- -into said path of saithopen latch to-;be moved: from :the v first to the: second, angulan position thereof ,-by engagement with, saidnopen latch.

6. In an; arrangement asnsettforthrin. claim 1, saidr secondifiontactsmember beingpivotablyr mountedron said support? and pi-votable into/,and-outof engagement with said first-c'cmtachmember about anaxis.

7. In an arrangement as set forth in claim 6, said, pivoting axis rot said second... contact member. being. substantially parallel; to ,the axis of said pivot means. I

8.v In.,,an; arrangement I as set .forthflinuclaim 1,, said feeler member and said trigger member, being v, fixedlyj mounted omsaid pivotmeansi and. radially projecting theresetting means secured to said second contact member and projecting from said casing.

12. In an arrangement as set forth in claim 1, said feeler member being fixedly mounted on said pivot means and axially adjustable thereon.

13. In an arrangement as set forth in claim 1, said trigger member being a two-armed lever, one of the arms thereof carrying said abutment means, and the other arm cooperating with said resilient means.

14. In an arrangement as set forth in claim 1, said abutment means being out of abutment against said second contact member when said feeler member is in the second position thereof.

15. In a stop-motion device for a knitting machine having a latch needle movably mounted thereon for movement of the latch of said needle in a predetermined direction and path when said latch is in the open position thereof, a casing; a first contact member fixedly mounted in said casing; a second contact member mounted in said casing, said second member being reciprocably turnable about an axis into and out of engagement with said first member for closing and opening a stop-motion circuit and having a stepped face portion; manual setting means secured to said second contact member and projecting from said casing; pivot means mounted on said casing for rotation about an axis substantially parallel to the axis of rotation of said second member; a feeler member fixedly mounted on said pivot means for turning movement about the axis thereof between a first and a second angular position, an actuating portion of said feeler member projecting from said casing and said casing being mounted on said knitting machine in such a manner that said actuating portion of said feeler member projects into said path of said open latch for movement thereby in said predetermined direction from the first to the second angular position of said feeler member; a trigger member fixedly mounted on said pivot means and connected to said feeler member for joint movement therewith about the axis of said pivot means, said trigger member having two arms radially extending from said axis; abutment means on one of said arms for abutment against one of the steps of said face portion when said feeler member is in said first position thereof so as to selectively prevent movement of said second contact member into engagement with said first contact member, said abutment means being out of abutment against said step when said feeler member is in the second position thereof; a resilient member having spaced portions respectively secured to said second contact member and to the other arm of said trigger member for permanently urging said second contact member to move into engagement with said first contact member, and for urging said feeler member to move towards said first position thereof.

References Cited in the file of this patent UNITED STATES PATENTS 1,979,208 Friden Oct. 30, 1934 2,036,243 Wachsman Apr. 7, 1936 2,241,720 Herman et al May 13, 1941 2,257,037 Crawford Sept. 23, 1941 2,636,367 St. Pierre et al. Apr. 28, 1953 2,661,615 Crawford et al. Dec. 8, 1953 2,832,856 Goodhouse Apr. 29, 1958 

